Motion pictures and apparatus therefor



Dec. 14, 1937. I Q ETZEL 2,101,842

MOTION PICTURES AND APPARATUS THEREFOR Filed March 25, 1934 8 Sheets-Sheet l al: Ha I.

-B;, dilzidrlgsfltggl, I v ZTOBNEYS.

Dec. 14, 1937. v C ETZEL 7 2,101,842 MOTION PICTURES AND APPARATUS'THEREFOR Filed March 23, 1954 s Sheets-Sheet 2 INVENTOR: I

Chales Eiyel? Dec. 14, 1937. c.- ETZEL MOTION PICTURES AND APPARATUS THEREFOR Filed March 23, 1934 8 Sheets-Sheet 3 I N VEN TOR:

Gharlas EZ 'eZ, BY fi \ZZZTORNEYS.

Dec. 14, 1937. c. ETZEL MOTION PICTURES AND APPARATUS THEREFOR 8 Sheets-Shet 4 Filed March 23, 1934 WI T181555? INVENTOR: Oharles EZ QZ,

ATTORNEYS.

Dec. 14, 1937'. I c ETZEL 2,101,842

- MOTION PICTURES AND APPARATUS THEREFOR Filed March 23, 1934 8 Sheets-Sheet 5 FI M [22 INPENTOR:

GizarZasEZ;eZ;

Dec. 14, 1937. 6. ETZEL MOTION PICTURES AND APPARATUS THEREFOR Filed March 23, 1954 8 Sheets-Sheet 6 QINVENTOR: ,OharZas Eiyel,

ATTORNEYS Dec. 14, 1937. c. ETZEL MOTION PICTURES AND APPARATUS THEREFOR 8 Sheets-Sheet 7 Filed March 25, 1954 RH A A A QAHQ g ms @H 4 Mn @NLW l N VEN TOR: Gizafles Eipel,

ATTORNEYS.

Dec. 14, 1937. c. ETZEL MOTION PICTURES AND APPARATUS THEREFOR 8 Sheets-Sheet 8 Filed March 25, 1934 FIG". 12%.

INVENTOR: harms EZ eZ, BY

. Patented Dec. 14, 1931 UNITED 5m MOTION mamas AND ArrAnA'rUs mmoa Charles Etael, Philadelphia, Pa., assignor, by mesne assignments, to Etzo Corporation, a corporation of California Application March 23, 1934, Serial No. 718,929

18 Claims.

This invention relates to motion pictures, and aims especially to reproduce in motion pictures the visual effects of depth, etc.', characteristic of .binocular vision: in other words, impressions of difference in the distances of different objects, of one being in front of another, and of the individual solidity or three-dimensional character of an object. while ordinary motion pictures can render diminution in size oi objects, indistinctness of detail, and the shadow eflects, etc., by which distance and solidity are in part instinctively inferred, they totally fail to render other very important factors or "clues" in our visual perception of depth and solidity, which depend on the cooperative vision of two eyes suitably separated.

An important feature of binocular vision is the automatic muscular coordination of the eyes commonly referred to as "convergency and divergency: the turning of the eyeballs in their sockets so as to direct (and converge) the axes of vision of both eyes on the spot or object that occupies the attention. From the different angular relations between the axes of vision required for objects at different distances, and the correspondingly different angular relations of the eyeballs and innervations of their controlling muscles, we subconsciously derive a sense of nearness and distance of objects. Another very important factor v is what is known as retinal rivalry": 1. e:, the fact that the-left eye can see "further around to the left of an object than can the right eye, and can thus often see more fiiectors) in their projectors.

of the left side of a solid than can the right eye, and can see some portion of the background of an object which is hidden from the right eye, and vice-versa. While the automatic adjustment of convergency and divergency permits an apperceptive synthesis or the slightly different images of the retinas of the two eyes, which results in our being normally unaware of the difference in these retinal images, yet this difference remains and is an important factor in our perceptions of depth, as well as of solidity. In view of these considerations, it is easy to understand why picture producers have been unable to remedy the impression of flatness in motion pictures by means of costly perspective stage settings, special grouping of actors, and intricate light effects, and why exhibitors have had no better success by using over-dimensioned mirror lampslas arc lamps with parabolic re- Such exhibiting practices merely burn out the fine'photographic effects and shadings of the film, overfiood the screen with light,- and cause serious eye-strain in theatre-goers; and stage-settings, groupings, and special lighting in production, etc., only improve the pictures in a two dimensional way.

I have found that the flatness of ordinary motion pictures can be obviated, and the desired three-dimensional effects realized, by embodying suitable clues or characteristics of binocular" vision in motion picture films themselves. For this purpose, in picture taking, a "visual analysis and a multiple photographic record of the scene and action are made, in a manner analogous to the actions of two eyes in binocular vision. This record embodies one or (preferably) both of the usual binocular clues: retinal rivalry and convergency-and-divergency. In projection, the diverse photographic components of the record are recombined in a manner analogous to the apperceptive synthesis of the two retinal images in ordinary vision, and so that the series of images on the screen evokes the usual mental responseto the binocular clue(s).

In taking pictures according to my preferred procedure, the exposures to produce the multiple photographic record are not made as from one single point, but as from positions of a stereoscopic or binocular range corresponding (more or less nearly) to the normal pupilar distance,--

. which is some 2 or 3 inches. In some cases, an exaggerated (or reduced) stereoscopic binocular range very different from the pupilar distance may be resorted to with good results-i but ordinarily this will not be necessary. Foreach positionof the range (actual or virtual) and for each exposure, the line of vision of the camera (the lens axis) is compensatively turned and directed (actually or virtually) so that the film-frame shall cover substantially the same field of vision, and substantially to the same (fixed) point or object oi. main interest in the subject or scene,

thus compensating for the diflerence in point of view of the exposures, and also paralleling the convergency-and-divergency of binocular vision. The motion of the camera (actual or virtual) over the binocular range (and likewise its compensatory turning movement or oscillation) may be uniform or otherwise; and exposures made from a multiplicity of points in the range of motion may thus represent either equal or unequal shifts in-the point of view: 1. e., the oflset from picture to picture may be either uniform or varied, With an ordinary motion picture camera, suitablev light-deflecting and transmitting means (reflectors or mirrors) interposed in its line of vision may be used to effect (virtually) a transverse shift or an angular deflection of the line of vision-or both-in a manner equivalent to corresponding actual movement of the camera. A mirror, however, need only be turned half as much as the camera would have to be turned for the same eflect of compensation.

In using a photographic record made according to my invention, the stereoscopic binocular film-frames or exposures (made as described from slightly different points of view) are prohibited with the usual projection apparatus, with-' entirely ignorant of its special character.

jected on the screen in the succession in which they were made. which gives the illusion of continuous motion in ordinary motion pictures produces such an ocular and mental synthesis of these slightly different film-frames as to give a clear-cut impresout any special measures, and even by operators other words, my invention can be successfully practiced with a single film strip hearing but one series of'exposures or film-frames. The

' exposures,-moreover, can be taken with a single ordinary motion picture camera,used, however,

in a special way such as hereinafter explained. Various other features and advantages of the invention will appear from the following explanation and description of species thereof, and from the drawings. v

In the drawings, Figs. I-Va are diagrammatic plan views illustrating the taking of motion pictures, with various different camera arrangements for the purpose. a

Figs. VI and VII are diagrammatic illustrations of film strip records taken in accordance with my invention.

Fig. VIII is a side view of one preferred form of apparatus for taking pictures according to my invention with a standard motion picture camera,which is shown in full lines operatively mounted on the apparatus. L

Fig. IX is a corresponding plan view, without the camera, 1

Fig. X'is a fragmentary plan view, on a larger scale than Figs. VIII and IX, with certain parts in horizontal section.

Fig. XI showsa vertical section through the apparatus, taken as indicated by the line and v arrows XI-,-XI in Fig. IX.

Fig. IE1 is a fragmentary view, showing a verticalsection taken as indicated by the line and arrows XII-XII in Fig. K.

Fig, XIII'is a fragmentary detail view, partly in vertical section as indicated by the line and arrows X[IIXIII in Fig. X. i

Fig. XIV is a plan view withthe upper camera and mirror-carrying structure removed, and certain parts in section.

Fig. XV shows a horizontal section through the base of the machine, with its driving connections thus exposed.

Fig. XVI shows a fragmentary vertical section, taken as indicated by the line and arrows The same persistence-of-vision frame in the pictures taken from the left-hand" L stage, substantially at the plane of the -prosce-- nium frame P. In order to clarify, certain points regarding the field view, let us suppose that the shape and proportions of the proscenium- -frame P correspond exactly to those of the film-frame in the motion picture camera C; that it is desired to show in the film-frame Just what appears in the proscenium frame, no more, no less; and that the camera C can be located at a position to accomplish this exactly: these, of course, are purely arbitrary conditions, that will rarely 'or never obtain in practice. suppose that the preferred stereoscopic binocular range of camera positions for exposures is that marked din Figs. I-V.

If exposures be made from each of the camerapositions C C in Fig. I, which are the distance d apart (on centers), with a single motion picture camera continually shifted back and forth transversely of its line of vision, and making its exposures at the positions C C? in alternation,

the result will be two sets of (negative) pictures,

alternating in a single series on the film, wherein the position of object 0 relative to its background (formed by backscene B) will be different. However, if the camera lens axes 1 Z remain parallel when exposures are made from C and C as shown in Fig. I, then convergency-and-divergency will not be incorporated in the sets of the pictures in any way; and if the proscenium-frame Pexactly coincides with the filmposition 0 it will not do so in those taken from the right-hand position C on the contrary, theselatter will show some of the frame? at the right, and will miss some of the scene within frame P at the left. In other words, the field of view will be changed.

These defects can be substantially corrected, however, by a slight compensatory deflection or convergence of the lens axes 1 l for the posi- XVI-XVI ii Fig. XV, illustrating part" of the operating connections to the camera.

Fig. XVII shows a similar fragmentary section,

r taken as indicated by the line and arrows connections to the camera. 7

Fig. XVIII shows a section taken as indicated by the line and arrows XVIIIXVIII in Fig.

Figs. I-V show in plan a stage S set as a room XVII-XVII in Fig. IX, at the other end of the ,for the filming of a motion picture scene, and

provided with a proscenium-arch or framed tions C C, as shown in Fig, II. With lens axes, 1 I? thus pointedat substantially the very same object or spot 0 from both the positions 0 C both sets of pictures will have the proscenium frameP in coincidence with the film-frame, and will properly embody the clue .of convergencyand-divergency. However, it is not necessary to make all exposures from the extremes of the range dz-on the contrary, some may be made from intermediate points. This is illustrated in Fig. III, where four camera positions C C C 0 are shown, with the 'lens axes l l 1 Z com.- pensatively deflected accordingly, so as to be directed on the "object 0 from each. of these positions. The camera positions C C C C are not in a straight line, but on the arc of a circle centered at the object 0, so that all theipictures are taken at a constant distance from the object,

1 and disparity of the pictures due to difference in distance is avoided. This is of advantage in making easier the mechanics of shifting the camera back and forth, since the camera need not travel the whole range :2 in the very brief interval between successive exposures. Obviously, there may be a greater or less number of intermediate exposure-positions in the range d. Moving slowly back and forth over the range d, the camera which are too brief tobe blurred ly very slow movement of the camera.

Let us also,

need not be halted for the intermediate exposures, by comparative- 20 the camera itself.

(50 pensing with repetitive description.

ing means such as reflectors (mirrors) interposed between the camera and the scene or object being filmed, the camera may or may not be shifted or turned: e. .g., the mirrors may be shifted or turned, or both, alike or differently, to produce the effect of shifting or turning the camera, or both. Fig. IV shows an arrangement in which the camera C is fixed on a stand or base 20 affcrding ways forthe reciprocation of a carriage 22 whereon coacting f45 mirrors M, m are mounted to turn about vertical axes 23, 23. These mirrors M, m receive the light from the subject or scene S and direct it into the camera C, deflecting the path of light from the scene-to the camera andoifsetting it laterally. A revolving crank disk 25 connected by a connecting rod 26 to the carriage 22 reciprocates the latter and its mirrors M, 111. through a range d, thus producing in the camera C an effect similar to that of shifting Either of the mirrors M, m may be pivotally connected at 21 or 23 to a link rod 23 which is in turn pivotally connected at 30 to a lever 3| fulcrumed at 32 on the stand 20,

and pivoted at 33 to an arm 34 on the carriage 22.

25 -Thus the mirror M or m is given a compensatory angular motion to and fro whose magnitude depends on the lever arms and thus on the relative position of the pivots 32. 33, 33. The eflect of this is similar to that of turning the camera C,-

30 except, of, course, that turninga mirror through a given angle is equivalent to turning the camerathrough double the angle. The mirror m or M that is not thus oscillated may be suitably held in a fixed (45 or other) position on the carriage Fig. V shows an arrangement in which the camera C is mounted on the carriage "use as to move to and fro withthe mirrors M, m, either of which may have a compensatory angular motion. The mechanism is the same as in Fig. IV,

and its various parts and features are marked with the same reference characters, as a means of dispensing with repetitive description..

Fig. Va shows an arrangement more or less similar to Fig.,IV, but using only a single mirror M and having the camera C pointed along the ways of the stand 20, transversely of the line of vision 1. Accordingly, the path of light from the subject S to the camera C is deflected and turned substantially 90 by the mirror M when in the .45" position of Fig. Viz. The mirror M moves toward and from the camera C in a binocular-flange d transverse to the line of vision I, and may also have a compensatory angular movement orswing, to and fro,'--equivalent to turning the camera C back and forthf The mechanism is similar to that in Figs. IV and V, and its parts land features are marked with the same reference characters, as ameans of dis- Fig. VI shows a strip of film resulting from exposures made at the extremes C C' only of the range if in Fig. II. Fig. VII shows a similar strip of film made with two additional, intermediate 65 exposures, so that the four exposures or filmframes correspond. successively to the different i. positions C C C3, C in Fig, III. In both cases, it will be seen, the position of the door lb in the back scene B varies relative to the object O,-this 7 variation being, of course, greatly exaggerated to make it apparent. In practice, the variation will be only enough to produce the retinal rivalry effect when the successive pictures are projected on the screen.

75 Figs. VIE-XVIII illustrate in detail a preferred ment.

form of apparatus for the purpose of my invention, in which a motion picture camera C is reciprocated to and fro, transversely of the line of vision or lens axis of the camera, over a stereo scopic binocular range, and can also be turned or swung to and fro. A pair of normally" parallel 45 mirrors M, m are interposed between the camera and the scene or objective being photographed, to receive light from the scene or offset portion of the light-path between the mir rors M,,m is changed. Each or either of these mirrors can be of single or multiple plane construction. The camera C is mounted (as by means of a dovetail socket 39) on a supporting structure or table 40 which also carries the mirrors M, m. The supporting structure or table 40 is movably mounted. on a carriage 4i so that it can turn or swing relative to the carriage; and the carriage 4i is movably mounted to slide on a base or stand 42 so that it can reciprocate relative thereto over any desired binocular range of move- As shownin Fig. XI, the table 40 is pivoted (with antifriction ball bearings) about an upstanding stud 43 on the carriage 4i, and is guided and steadied, so as to swing freely without sidewise or tipping play, by V-faced guide segments 44 detachably mounted on the carriage,

and cooperating with V-grooved guide rollers 45' mounted on the table 40, preferably with antifriction ball bearings. Fig. IX shows in dot-anddash lines a/standard motion.,picture camera C mounted on the table 40 in such position that the axis of the pivot 43 about which the table 40 oscillates relative to the carriage 4| passes through the superjacent lens opening 53 cf the camera (Fig. VIII) and through the optical axis of the lens. The base 42 is shown as a hollow cast metal structure, and is provided with parallel, opposed, internal V-faced guideways 43, 46 along its upper edges, each of which ways 46, 46 cooperates with a pair of V-grooved guide rolls 41, 41 mounted on the carriage 4|. The base 42 .is also shown provided with suitable means of support or attachment, such as' feet 48 (Fig. VIII). Thecarriage 4i has the form of a plate which partially covers the otherwise open top of the base 42, and protects the rollers 41 within the base, As best shown in Fig. XI, the dovetail socket 33 for mounting the camera C is in a part.

49 adjustable in the direction of the lenrfiaxis or line of vision of the camera along guideways 50 on the table 40.

As shown in Figs. XI and XII, the object or light-entrance mirror M andthe camera or lightexit mirror m are removably mounted in holders Si, 52 which are rotatably mounted on upstanding bosses or hubs 53, 53 on the table structure 40,

'by means of pivot spindles 54, 55 rotatable in said bosses, preferably with antifriction ball bearings. Thus the mirrors M, m can turn freely relative to the table 40, without looseness or possibility of side play of any kind. The mirrors M, m are enclosed in. a sheet metal casing 51. detachably mounted on the base structure, and provided with an opening 33 in its rear side for the lens shown in Figs. VIII, X and IX, a flaring hood 6| opening or barrel 68 of the camera 0, asweil as with a much larger, opening 68 to admit the light from the objector scene tobe photographed. As

may be detachably mounted on the front of the casing 5'! around the opening 68. The insideof casing 6! and hood 6| are preferably finished in dull black or other non-reflecting finish.

For actuating the carriage 4|, there is in the base 42 a crank device 62 whose upright shaft axis 63 (preferably mounted in antifriction ball bearing) is driven by a worm wheel and worm gear 64, 65, enclosed ina casing 66 detachably mounted on the bottom of the casing 42. The worm shaft 61 (preferably also mounted in antifriction ball bearings) may be driven or operated by any suitable means, such as a crank 68 connected to the shaft 61 through change speed gearing in'a compartment or casing 68 on the base 42 (Fig. XV) A slide block 18 revolubly mounted on the crank pin ll (withinterposed antifriction ball bearings) cooperates with a guide groove'or slideway 12 in the lower side of the carriage plate 4|. As the crank 62 rotates at uniform speed, it reciprocates the carriage 4| (harmonically) over a range determined by the eccentricity of the crank pin ll with reference to the shaft 68, To permit adjustmentofthe'crankmin H to vary its eccentricity and thus adjust the amplitude of movement of the carriage 4|, the crank pin II is mounted on a block I3 which is slidable radially along the crank arm 62; The block 13 may be adjusted and set in any desired radial position bymeans of an endless screw 14 whose ends are mounted in bearings at the inner and outer ends 'of the crank arm 62, and which is in threaded engagement with a downward projecting nut portion of the slide block 13. As shown, the outer endless screw bearing 15 is detachably secured to the crank arm 62. Beyond the bearing 15 is a polygonal-socketed sleeve 16 secured on the end of the screw 14 by a diametral pin 11. A polygonal key for turning the screw 14 may be inserted through an opening 18 in the base 42 J I plitude of swing of the table 48 about its axis 48,

when the crank arm .62 is turned to a suitable position to permit this. 4

The table 48 may be turned relative to the carriage 4| by any suitable means, here shown as an operating connection between I the table 48 and the base 42. As shown in Figs.

IX, XI, and XIV, the connection comprises a' follower slide block 18 (similar to the slide block 18) pivotally mounted at the lower side of the tablestructure 48 and engaging and cooperating.

in a cam groove or slideway 88 in a "tangent bar" or swung to and fro member 8| located above the carriage 4| and extending (in the general directionof the carriage movement) from end to end of the base 42,

transversely of the lens axis or line of vision of the camera. As shown in Fig. XIV, one end of the member 8| is pivoted to the base 42 at 82, beyond theextreme range of travel of the table 48,

and its other end extends into a gear casing 88 detachably mounted on this end of the base 42. The end of the member 8| has rack teeth 84 which mesh with a worm 85 mounted in bearings in the removable ends of the gear casing 83. -By

turning the worm 85 one way or the other, the

camway 88 can be'adjusted to any desired angle of divergence relative to the direction of travel of the carriage 4|, so as to oscillate or swing the table 48 about its axis 43, as the carriage reciprocates, through any desired amplitude of movement within the rangeo'f adjustment. As shown min Fig. IX. the shaft of the worm 86 has a Y knurled knob 86 to which is clamped, by a screw 81, aspirally, grooved barrel-68: "The barrel 88 is graduated as shown in Fig'g'IX for cooperation with a pointer 88 on .a slid'e='88*that slides in-a*--' suitable slideway in tlie gear-casing 86, and has a 1 projection 8| engaged in a spiral groove 92 of til the barrel 88. This arrangement, it will be seen," permits very delicate adjustment of the inclina-' very same object in 'the scene. As the pivot-axis for the swinging movement is at the lens barrel .or opening 68,-at the lens tube of the camera,

- to use a generic term,the swing of the camera introduces no complications though it does not obviate the change'inthe effective length of the light-path from subject to camera that is prop duced by the (straight) transverse movement of the camera. In compensation for this, however, an opposite change in the effective length of the light-path is produced by the swinging ofboth mirrors M, m through equalangles concurrently with the transverse movement and swing of the camera C, as described hereinafter: i. e., as the mirrors swing while remaining parallel, the offset portion of the light-path from one mirror to the other is shortened or lengthened. Thus the virtual distance of the camera C from the object remains constant, as in Fig. III. The importance of thus keeping the effective length of the lightpath from subject to camera substantially constant-notwithstanding the transverse movement and swing of camera Owith carriage-4| g and table 48,-'-is of course, to avoid noticeable changes in the apparent magnitude of objects in barrel 88 cooperating with the pointer 88,the camway 88 can be instantly adjusted to vary the amaccording to variations in dista'nceof the princi-" pal object in the scene from the camera,'as when the picture. By the use of the-knob 86 with its a an actor walks toward the camera or away from 1 it. This corresponds, ofcourse, with the varying paralax in binocular vision according to the distance of the object from the observer. The adjustment is facilitated, of course, by suitable graduation of the scale onbarrel 88 according to various distances of the object from the camera. as illustratively indicated by the numerals '|,8, I6, 38, 48, 58, etc., shown in Fig. IX; I

The light entrance or object mirror M and the light exit or camera mirror m (one or both) may be operated by any suitable means, such, for example, as an operating connection to the carriage 4|. As shown in Figs. VIII, X,.XI, and XII, a segmental gear 84'concentric with the table axis 48 is fixedly. secured to the carriage 4| by said axis 43 and a screw 66. The segmental gear 84 meshes with an idler pinion 86 (preferably mounted with antifriction ball bearings) at the lower side of--the table 48,'and this pinion 96 meshes with .a segmental gear 81 on a crank arm 88 detachably secured to the lower end of the spindle 66 of the camera mirror m, and concentric with this spindle. As shown in Fig. XI, pro-r vision is made for angular adjustment of the crank arm 08 relative to the spindle 55, by means of a friction clutch connection comprising a conical cup member I keyed fast to the lower end of the spindle 55 and a conical hub IOI on the upper side of the crank arm 38. The hub IOI can be clamped tight in the cup I00 by any suitable means, such as a screw I02 taking into the lower end of the spindle 55, and associated washers I03, I04. The mounting 52 of the mirror m may be detachabiy secured to the upper end of the spindle 55 by a set screw I05: in Fig. XI, it is shown turned out of its normal angular relation to the spindle 55, at right anglesto the plane of the paper. The crank arm 00 is connected by a link rod I06 to a similar crank arm I00, of the same effective radius, which is keyed fast on the lower end of the spindle 54 of theiight-entrance mirror M. Mounting 5I of mirror M is detachably secured to the upper end of the spindle 54 by a set screw I09. As shown and indicated in Figs. XI and XII, the pivotal connections of the link rod I05 to the crank arms 08, I08 may be provided with antifriction ball bearings, so that there shall be no back-lash. Through the connections just described, both mirrors M, m are turned relative to the table 40, as the latter swings, with a rotation opposite to that of'the table relative to the carriage II, and at a rate depending upon the gear ratios or radii of the segmental gears 94 and 31. It is this turning or swinging of the mirrors M, m that is referred to above as compensating for the change in the effective length of the lightpath due to the'transverse movement of the camera. Obviously, this gear ratio may be changed practically as desired by substituting a larger or smaller idler .96 and corresponding changing of the segmental gear 94 and the crank arm 00 with its gear 01. Obviously, also, the amplitude of swing of the mirrors M, m varies with the swing.

of table 40, since this directly produces the swing of the mirrors as described above.

When desired, the camera mirror m may be disconnected from the crank arm 08 by means of the screw I02,.etc., without interfering with the continued operation of the light-entrance mirror M. When the mirror m is thus disconnected, it may be locked in fixed 45 (or other desired) position relative to the camera as shown in Fig. XIII, by means of a locking pin or bolt IIO movable longitudinally in a boss III on the table and provided with a conical end for engaging a. conical socket in an arm II2 on the mirror mounting 52. When not in use, the bolt IIO may be retracted downward. by its knob H3 against the resistance of a spiral spring H4 in the boss III, so as to free the mounting 52 for unrestricted movement, and may be locked in retracted position by /giving it a 90 turn either way and then releasing it. In retracting the bolt IIO, a diametral pin II5 fixed therein is withdrawn from a slot H5 in a downward extension of the boss III; and when the bolt H0 is turned 90 and released, the pin II5 engages in a diametral notchI I1 in the outer end of said boss.

As shown in Fig. XV, the change speed gearing in compartment 60 on base 42 includes three gears I22, I23, I24 fast' on the worm shaft 51, and three corresponding gears I25, I25, I21 fast on a sleeve I20 splined to the shaft I20 0! the crank 00. The sleeve I20 may be shifted ion" gitudinally of shaft I23, bring any desired pair of gears into mesh, by means comprising a crank shaft I30 mounted in a bearing boss on the side of the gear casing 53 and having an inner crank arm with a disc I3I at its upperend engaged in a groove between the gears I25, I26, and an outer crank arm provided with an operating handle I32. As shown, the crank 68 is of variable radius, comprising a member I33 slidable in a diametral dovetail groove I34 in a fiy-wheel disc I35 keyed fast to the end of the shaft I29. A spring pressed ball catch I36 in a recess in the disc I35 is adapted to cooperate with any desired one of a series of conical socket recesses I31 in the inner side of the slide I33, to lock the slide in various radial positions.

As shown in Figs. VIII, IX, and*XV-XVIII, a flexible driving connection is provided for operating the motion picture camera C from the main drive shaft I29. For this purpose, there is a worm gear connection I40, I4I from theend of the drive shaft I29 to a spindle I42 (Fig. XVI) mounted in (antifriction ball) bearings in the base 42 and connected as shown to a flexible shaft I43 in a flexible cover I44. To the other end of the cover I44 is secured a casing. I45 (Figs. XVII and XVIII) which contains a revolving polygonal-socketed hub I45 adapted to engage the usual polygonal end of the operating shaft (not shown) of a standard motion picture .camera. The socket hub I46 has helical gear connections I41, I48 to a revolving sleeve I49 mounted (in antifriction ball bearings) in the casing I45 and splined at I50 to a spindle I5I connected to the flexible shaft I43. The casing I45 is provided with a split collar I52 which may be clamped by a screw I53 to a suitable boss (not shown) on the motion picture camera.

By suitable setting of the slideway 80 and selection of the gear ratio 94/97, various modes of operation are possible. For example, with a fairlylarge inclination of the slideway 80, and a suitable gear ratio, the swing of the table 40 and camera C may be mainly or altogether re-. lied on to compensate for the lateral shift of the carriage 4|, and the mirrors M, m may be swung together (remaining parallel, and with a rotation the reverse of that of the table) just enough to ofiset their change of direction due to the swing of the table. Or the camera mirror m may be released from the arm 08 and M making up the balance of compensation required. Or a slide setting and gear ratio intermediate those just indicated may be used. With the slideway 80 set parallel to the slideways 45, 46, there would be no turning of the table 40 or of the mirrors M, m.

The gear ratios of the change speed gearing at 69 may be such as to provide for film speeds of 24, 48, or '72 film-frames per second when the crank 58 is turned so as to give one complete back and forth movement of the carriage 4| every two seconds. Or if the gear ratios at 59 weresuch as to give a rapid table movement and an exposure at each end 0! the table travel, the harmonic movement of the table would give a dwell of the camera suiflcientlfcra compara;

tively long exposure. All of these supposed gear ratios, of course, are merely illustrative of what is possible.

Having thus described my invention, I claim:

1. A method of taking motionpictures affording the effect of three dimensions, which method comprises .deflecting the path of light from the scene or subject being photographed to the camera, shifting the :camerato and. fro transversely over a stereoscopic binocular range,

,compensatively swinging the camera about an axis at its lens tube to keep its line of vision directed toward the same object in the scene,

and concurrently varying the deflection of the light path so as to keep its length substantially constant, notwithstanding the other changes.

2. A method of taking motion pictures affording the effect of three dimensions, which method comprises deflecting and thereby ofisetting the path of light from the scene or subject being photographed to the camera, shifting' the camera to and fro transversely over a stereoscopic binocular range, compensatively swinging the camera about an axis at its lens tube to keep its line of vision directed toward the same object in the's'cene, and concurrently varying the length of the offset portion of the light-path so as to keep its total length substantially constant, notwithstanding the other changes.

3. Apparatus for taking motion pictures affording the eifect of three dimensions comprising, in combination with a motion picture camera, means for shifting said camera to and fro transversely over a stereoscopic binocular range, means for concurrently and compensative- 1y deflecting the line of vision of the camera according to its momentary position, and means for varying the relation between the deflection and the transverse shift of the camera as required by its,momentary distance from the ob- Ject, whether the-latter is at rest,advancing,-or receding, even' during the operation of the camera and of said shifting and deflecting means.

4. In apparatus for taking motion pictures affording the effect of three dimensions, .the com- 1 bination of a supporting base and amotion picture camera mounted thereon for movement relative thereto as hereinafter set forth, means for shifting said camera to and fro on said base,

traimversely of its line ofvision, over a stereoscopic binocular range, means for concurrently and compensatively swinging the camera about an axis at its lens tube to keep the line of vision of the. camera directed toward the same object in the scene or subject being photographed, and

means on the base connectedto the swinging means for varying the swinging movement in relation to the transverse movement of the camera.

5. In apparatus for taking motion pictures affording the eflect of three dimensions. the combination of a motion picture camera, means for shifting the camera to and fro transversely over a stereoscopic binocular range, means for deflecting the path of light from the subject ,or scene being photographed to the camera, and means for compensatively swinging the camera about an axis at its lens tube and varying the deflection of the light-path, so as to keep the line of vision of the camera directed toward the same object in the scene, and also to maintain the length of the light-path substantially constant, notwithstanding the other changes.

6. In apparatus for taking motion pictures affording theeifect of three dimensions, the combination of a motion picture camera, means for shifting the camera to and fro transversely over a stereoscopic binocular range, means for deflecting the path of light from the subject or scene being photographed to the camera, means for compensatively swinging the camera about an axis at its lens tube and varying thedeflection of the light-path, so as to keep the. line oi vision of the camera directed toward the same object in the scene, and also to maintain the length of the light-path substantially constant,

notwithstanding, the other changes, and means operable while the camera and said shiftingand swinging means .are in operation for varying the swinging movement in relation to the transverse movement of ,the camera, according to variations,

in the-distance of the object from the camera.

'7. In apparatus for taking motion pictures affording the effect of three dimensions, the combination of a shiftable and swingable motion picture camera, swingable reflector means for receiving light from the subject or scen'e being photographed and directing it into the camera, means for shifting the camera to and fro transversely over astereoscopic binocular range, means for compensatively swinging the camera and re flector means and thereby compensatively deflecting the line of vision of the camera so as to keep it' directed toward the same object in the scene, and means operable while the camera and said shifting and swingin'gmeans are in operation for varying the swinging movement in relation to the transverse shift of the camera, for the purpose of keeping the line of vision of the camera directed to the object notwithstanding variation of its distance from the camera. 8. In apparatus for taking motion picture at fording the eifect of three dimensions, the combination of a base and a carriage sliding and recip- --rocable thereon through a stereoscopic binocular range, a supporting structure movably mounted binocular. range, a supporting structure movably mounted on said carriage, for swingingmotion about an axis relative to the carriage, means on said supporting structure for mounting a camera with its lens tube at the axis of swinging motion of said structure, and means operable while the camera and said last-mentioned means are.in operation for varying the amount of swing of the supporting structure in relation to therecipr'ocation of the carriage.

10. Apparatus for taking motion pictures affording the effect of three dimensions, comprising, in combination with a motion picture camera, means for shifting said camera transversely over a stereoscopic. binocular range, reflector means interposed in the line of vision'of said camera, means for swinging said reflector means to thereby compensatively deflect the line of vision in correspondence with the transverse movement of the camera, means including a common drive for actuating said shifting and said swinging means, and operating said camera, and means I v 2,1Q1,849 operable while the camera and said shifting and swinging means are in operation for varying the swing of said reflector means in relation to the transverse shift of the camera, according to variations in the distance 01 the object from the camera. g 11. Apparatus oi! the character described comprising a carriage reciprocable transversely oi. the line or .vision or a motion picture camera carried by said carriage, a supporting structure swingable on said carriage and provided with means for mounting the camera, reflector means swingable on said supporting structure, and means for reciprocating said carriage, swinging said support-- ing structure relative thereto, and swinging the reflector means relative to said supporting structure.

12. Apparatus of the character described comprising a carriage reciprocable transversely of the line of vision or a motion picture camera Cal! ried by said carriage, a supporting structure swingable on said carriage and provided with means for mounting the. camera, reflector means swingable on said supporting structure, means for reciprocating said carriage, swinging said supporting structure relative thereto, and swinging the reflector means relativetosaid supporting structure, and means operable while the camera and said last-mentioned means are in operation for varying the swinging movement in relation tothe transverse movement of the carriage, aceor'dingto variations in the, distance of the object from the camera. v

13. Appaiat of the character described comprising a carri ge recip'rocable transversely of the line of vision of a motion picture camera carried by said carriage, a supporting structure swingable on said carriage and provided, with means for mounting the camera, reflector means swingable on said supporting structure, and means actuated by a common drive for reciprocating said carriage, swinging said supporting structure relative thereto, swinging the reflector means=relative to said supporting structure, and operating said camera.

14. Apparatus of the character described cornprising a carriage reciprocable transversely of the line of vision of a motion picture camera carried by said carriage, a supporting structure swingable on'said carriage and provided with means iormountingthe camera, reflector means swingable on said supporting structure, -and means for reciprocating said carriage and compensatively swinging said supporting structure relative thereto, and for reversely swinging the reflector means relative to said supporting structure tooflset the swing of the latter.

15. Apparatus of the character described comprising a hollow base provided with guideways,

a carriage on said base reciprocable along said guideways, actuatingmeans in said base for, reciprocating said carriage, a'supporting tructure swingable on said carriage and provided with means for mounting a motion picture camera, means forming an operating connection between said supporting structure and said base for swinging said supporting structure 'as said carriage reciprocates, reflector means for cooperating with, said camera swingable on said supporting structure, and means forming an operative connection between the reflector means and said carriage tor reversely swinging the re- V flector means relative to said supporting structure as the latter swings.

16. Apparatus of the character described comprising a hollow base provided with guideways, a carriage on said base reciprocable along said guideways, actuating means in said base for reciprocating said carriage,.a supporting structure swingable on said carriage and provided with means for mounting a motion picture camera, a camway mounted on said base above said carriage adjustable to varying inclinations relative to the movement of the latter, and follower means on said supporting structure cooperative with said camway to swing'said supporting structure as said carriage reciprocates, reflector means for cooperating with said camera swingable on said supporting structure, and means forming an operative connection between the reflector means and said carriage for swinging the reflector 'means relative to said supporting structure as the latter swings.

17. Apparatus of the character described comprising a hollow base provided with guideways, a carriage on said base reciprocable along said guideways, actuating means in said base for harmonically reciprocating said carriage, a supporting structure swingable on said carriage and provided with means for mounting a motionpicture camera, a camway mounted on said base above said carriage adjustable to varying inclinations relative to the movement of the latter, and follower means on said supporting-structure cooperative with said camway to swing said supporting structure as said carriage reciprocates, reflector means for cooperating with said camera -swingable 'on said supporting structure, and means forming an operative connection between the reflector means and said carriage for reveisely swinging the reflector means relative to said supporting structure as the latter swings.

18. Apparatus of the character described comprising a hollow base with opposed internal guideways; a carriage on said base provided with :rollers between and coacting with said guideways, and also provided with a slideway transverse to said guideways; drive means including a crank in said hollow base revolving in a plane substantially parallel with said guideways and the range of movement of said carriage; s. supporting structure pivoted on .said carriage and provided with means for mounting a camera, and coacting roller andarcuate guide means on 'said supporting structure and carriage for steadying the one relative to the other; means forming an operating connection between said supporting structure and said base for swinging said supporting structure as said carriage reciprocates, with provision for adjustment to vary the swing;

reflector means for cooperating with said camera swingable on said supporting structure; means forming an operative connection between the reflector means and said carriage for swinging the reflector means relative to said supporting structure as the latter swings; and a flexible connection from said drive means for operating a motion picture camera mounted on said supportin structure. 

